Hello: The function hol_append() in lib/argp-parse.c exhibits undefined behavior. Specifically, the expression in line 894:
e->short_options += (short_options - hol->short_options); subtracts two pointers that do not point to the same memory object. Something like: e->short_options = short_options + (e->short_options - hol->short_options); does the intended operation with legal pointer arithmetic. I found this issue with the help of SAFECode (http://safecode.cs.illinois.edu/). Matt
